Sheet moistening device for duplicating machines



Sept-10, 1946. 2,407,443

SHEET MOISTENING DEVICE FOR DUPLICATING MACHINES I E. W. PETERSON Filed March 16, 1945 2 Sheets-Sheetl 'INVENTOR. E'rz'c ZlfReierson.

Sept. 10, 1946. E. w. PETE RSON 2,407,443

SHEET MOISTENING DEVICE FOR DUPLICATING MACHINES Filed March 16, 1945 2 Sheets-Sheet 2 Islam-1 h I I c, 111ml gunugmzalnm Patented Sept. 10, 1946 UNITED i I r 2,407,443

SHEET MOISTENING DEVICE FOR DUPLI- CATING MACHINES Eric W. Peterson, Glen Ellyn, 111,, assignor to Ditto, Incorporated, Chicago, 111., a corporation of West Virginia Application March 16, 1945, Serial No. 583,060 I V. 1 The present invention relates to improvements in a moistening mechanism for moistening copy sheets in a liquid process duplicating machine wherein the copy sheets are moistened with a solvent for the ink in whichthe matter to be copied is provided in reverse vupon the master sheet, the master sheet .being mounted upon a suitable drum. My invention is particularly directed to an improvement in oneform of moistening device shown in the application of George J. Rundblad,.

Both of these characteristics tend to cause loss of the liquid wherever. it is exposed to atmosphere or to a surface along which it may creep to further spread itself and increase its evaporation. My invention contemplates the provision of a novel construction whereby the liquid supply means supplying the moistening liquid is sealed at all times when the duplicating apparatus is at rest. The sealing is accomplished in such fashion as to'avoid the necessity of any special adjustment by the operator. Furthermore, the actual accomplishmentof scaling is done as an auxiliary act in connection with the positioning of the duplicating apparatus in so called home" position. Y

The nature and advantages ofmy invention will appear more fully from the following description and the accompanying drawings wherein a preferred form of the invention is shown. It should be understood however that the drawings and description are illustrative only and should not be taken as limiting the invention except insofar as it is limited by the claims.

' In the drawings:

Figure 1 is a longitudinal sectional view through a portion of a duplicating machine of the type'above referred to showing my invention as applied thereto;

Figure 2 is a fragmentary sectional view taken on the line 2-2 of Figure 3;

Figure 3 is a fragmentary sectional view taken on the line 3? 3 of Figure l; v

Figure 4 is a fragmentary sectional view taken on the line 44 of Figure 1; l

Figure 5 is an enlarged fragmentary sectional view taken on the line 55 of Figure 3; and

Figure 6 is a view similar to Figure 5 but showing the parts in a changed position. 7

Referring now to the drawings, my invention is embodied in a liquid process duplicating machine wherein a drum I0 is mounted in suitable side frames II and I2 by means of a shaft I3. The side framesare preferably in the form of fiat sheets punched with the necessary openings for mounting bearings and the like. These side frames. are covered by housing members I4 and I5 of relatively thin sheet material shaped to provide the necessary space for the parts outside of the frames I I and I2 and to present a pleasing exterior appearance.

The drum I0 is. adapted to carry a master sheet I6. The drum is provided with a clamping means I! whichis suitably operated to clamp or release the master'sheet by suchmeans as that shown in theapplication aboverreferred to. A platen roller I8 cooperates with the drum'to press copy sheets against the master sheet I6 after the copy sheets have been moistened. A copy sheet receiving tray I9 is mounted between the side frames II and I2 in a position to receive the copy sheets from the drum.

The duplicating machine is provided with a pair of combined feeding and moistening rollers and 2|, the roller 20 in the present instance being the moistening roller while the roller}! is a counter roller, spring pressed toward the moistening roller 20, The moistening roller- 26 has a shaft 22 which is journalled in suitable bearings 23 and 24 that are provided in the side frames vII and I2. The counter roller 2| has a shaft 25 which is reduced in diameter at its end to receive two bearing blocks 26 and 21 (se Figures 2 and 3). These bearing blocks are slidable vertically in suitable apertures provided in the side frames II and I2 and are sprin pressed upwardly by two plungers 28 and 28. The plungers are mounted in adjustable hollow screws 3!! and 3| that are threaded in two brackets 32 and 33.

Immediately in advance of the rollers 20 and 2| I provide a guide channel for directin copy sheets between the rollers. This guide channel comprises a lower plate 34 which is carried upon a cross tie bar 35between the side frames I I and I2, and an upper plate 36 which is fastened to the side frames II and I2 by suitable screws shown at 31 in Figure 1. Figure 1 shows a copy sheet 38 being advanced by a feed roller 39 to the rollers 20' and 2 I. A feed tray 40 is mounted .from the receptacle 4| down through the rib 42 into the boot 43. This boot 43 has a plurality of openings 44 in the side face thereof that is directed toward the roller 28. Likewise, the boot has ribs 45 at its opposite ends which project forward above the level of the openings E4 to engage the surface of the roller adjacent its ends and formed with the boot and the roller a trough into which liquid is fed through the openings 44. This trough provides a continuous uniform supply of liquid for moistening the roller as it retates downwardly across the face of the boot. The boot surface itself serves as a means of limiting the amount of liquid that will be carried downward by the roller into engagement with a copy sheet. When the supply of liquid in the trough falls below the top level of the openings 44 air can enter the lower portion of the boot and thus pass upwardly into the receptacle 4! allowing more liquid to flow through the openings 44. However, the trough still remains filled with liquid at all times regardless of whether the machine is running, and if there should be an air leak by evaporation of the liquid by the level of the openings 44 or by virtue of a poor closure of the valve that controls the outlet of the receptacle 4i, liquid can continue to flow while the machine is idle until the contents of the receptacle are exhausted. According to my invention, 1 provid means to overcome this difiiculty.

In order that my invention may be fully understood a more detailed description of the receptacle M, the mounting of the boot 43 thereon, and the valve arrangement for the receptacle will be given. The receptacle 4| is pivoted by two stub shafts 46 and 4i to the side frames H and I2. the arms being fixed to the shafts. The lever arms are biased downwardly by suitable springs 55 and El which are connected by two links 52 and 53 to adjusting screws 54 and 55 which are threaded into lugs 53 and 57 that are carried by I the side frames H and [2. This construction provides means for yieldingly pressing the lower end of the receptacle 41 toward the drum it] so as to maintain the normal running pressure desired between the boot 43 and the roller 20. The

boot 43 is clamped to the rib 42 by a series of bolts 58 spaced longitudinally along the rib. On one side there is a strip 59 of metal interposed between the heads of the bolts 58 and the wall of the boot 43 so as to uniformly press the boot against the rib 42. On the side of the rib a strip Bil of metal is formed to provide a splash shield portion i and a boot engaging portion 82 that is held against the boot 43 by the bolts 58. It will be noted that the lower end of the rib 42 is bevelled as shown at 63 in the opposite direction to the slope of the bottom portion 54 of the boot 43. However, the entire lower end of the boot 43 is beyond the rib 42 so that it is free to yield under pressure. The boot 43 is made of some resilient material, for example, crude rubber, or a synthetic rubber such as neoprene or Buna S may be used.

The rib 42 has a central aperture 65 extending upwardly therethrough into the receptacle The shafts have lever arms 48 and 49, 1

4|. The receptacle has an upstanding hollow valve housing 66 in the bottom thereof. The housing 66 has a side opening 61. Within the housing 66 there is a valve 68 which has an opening 69 that can be moved into and out of register with the opening 67 by turning the valve 68. Th valve 68 is open at its bottom end and bears upon a gasket ill which is apertured to establish communication with the opening 65.

The receptacle has a sealed cover ll and the valve 68 has a stem l2 that extends through the cover ll having a liquid tight packing around it to revent air from getting into the receptacle at the top. A finger piece 13 is mounted on the stem 12. The operation of the valve 68 is essentially the same as that described in the application hereinbefore identified.

Referring now particularly to Figures 1, 5, and 6 it will be noted that the sub shaft 41 has a collar l4 keyed thereto, and this collar has a lever arm 75 fixed thereon. The lever arm 15 carries a roller 16 at its free end, the roller being adapted to'engage a cam member 11 that is adjustably mounted on the drum ll] by means of two elongated slots 18 and 19 in the cam member and two screws and 8! that are threaded into the drum for clamping the cam member Tl in position. The elongated slots 18 and 79 provide for adjustment of the cam member both radially of the drum and circumferentially of the drum because the apertures are arranged at an angle to each other. In normal home position of the drum, a cam 82 (see Figure 1) is so mounted that a notch 83 therein is engaged by a roller 84 that iscarried at one end of a ball crank lever 85. The other end of the lever is connected to a spring 85 which is fixed to a pin 87 on the side frame of the machine. Normally the roller i6 rides along the surface of the drum at the end thereof beyond the master sheet !6 during the greater part of the cycle of operation. However, when the drum approaches home position the roller 84 starts to drop into the notch 83 at the time the roller '16 starts to climb the cam surface 1?. When the roller '16 rides up on the cam surface it turns the shaft 4'! through the connection provided by the lever arm 15. This in turn starts the receptacle 4i to rotate forcing the boot 43 toward the roller 25 and distorting the boot to the position shown in Figure 6 of the drawings. The net result of this operation is to seal the openings 44 by providing direct pressure contact at 88 and 89 around the openings 44 between the boot and the roller 29. It is evident that a certain amount of the liquid in the trough between the boot and the roller will be squeezed upwardly by this action to lie between the roller and the boot and between the end ribs 45. However, this small amount of liquid will soon evaporate or spread along the roller 20 and thus leave a Very small amount of liquid. After that further escape of liquid from the receptacle 4! is prevented by the seal around the openings 44.

In normal vertical operation of the machine the liquid remaining in the trough at the end of each cycle of operation is adequate to insure quick moistening of the roller 2 at the beginning of a n w cycle when the receptacle 4! sends back to normal operating position. However, when the machine has been idle for some time it is advisable to prime it by running the machine through one cycle of operations or possibly two cycles before actually beginning to make copies. It is believed that the nature of my invention will be clear from the foregoing description. The

principal advantages are in the provision of a means for sealing off the moistening liquid at the end of the duplicating operations. ual pressing and resilience of the boot 43 is not adversely affected. However, if the machine is allowed to stand idle for days at a time the boot may eventually take a permanent set and have to be replaced just as any resilient device of this character has to be replaced. Otherwise the seal of the liquid receptacle against leakage of its contents While the machine is idle, remains effective at the end of each cycle of operations of the duplicating machine.

Having thus described myinvention, I claim:

1. Moistening means for duplicating machines comprising a moistening roller, a resilient hollow boot having a side face engaging the roller, an aperture in the boot above the normally engaging surfaces of the roller and boot, whereby to pass liquid to the roller from within the boot, means to supply liquid to said boot, and means to press said boot and roller together to seal said aperture.

2. A duplicating machine having a frame, a drum therein adapted to support a master sheet, a moistening roller operable to moisten the surface of a copy sheet advancing to the drum, drive means operable to rotate the drum through repeated cycles, means for moistening said roller comprising a resilient hollow boot having a surface in engagement with the roller and having an aperture above the engaging surfaces of the boot and roller to supply liquid to the surface of the roller from Within the boot, a liquid supply receptacle connected to the boot, and means operable by the drum rotation periodically to compress the boot against the roller around said aperture and thereby seal the aperture.

3. A duplicating machine having a frame, a drum therein adapted to support a master sheet, a moistening roller operable to moisten the surface of a copy sheet advancing to the drum, drive means operable to rotate the drum through repeated cycles, means for moistening said roller comprising a resilient hollow boot having a surface in engagement with the roller and having The continan aperature above the engaging surfaces of the boot and roller to supply liquid to the surface of the roller from within the boot, a liquid supply receptacle connected to the boot, and means operable by the drum at the completion of each cycle of the drum, to form the boot wall about said aperture into engagement with the roller and thereby seal the aperture.

4. A duplicating machine having a frame, a drum therein adapted to support a master sheet, a moistening roller operable to moisten the surface of a copy sheet advancing to the drum, drive means operable to rotate the drum through repeated cycles, means for moistening said roller comprising a resilient hollow boot having a surface in engagement with the roller and having an aperture above the engaging surfaces of the boot and roller to supply liquid to the surface of the roller from Within the boot, a liquid supply receptacle carrying said boot and movably mounted on the machin frame, and means operable upon rotation of the drum periodically to move the receptacle to compress the boot against the roller and seal the roller. v

5. A duplicating machine having a frame, a drum therein adapted to support a master sheet, a moistening roller operableto moisten the surface of a copy sheet advancing to the drum, drive means operable to rotate the drum through repeated cycles, means for moistenin said roller comprising a resilient hollow boot having a surface in engagement with the roller and having an aperture above the engaging surfaces of the boot and roller to supply liquid to the surface of the roller from within the boot, a liquid supply receptacle having a rib at the bottom on which the boot is fixed and from which the boot projects into engagement with the roller, said receptacle being pivoted on the frame, a lever arm on the receptacle and a cam on the drum operating to swing the receptacle at the completion of each cycle of the drum, to form the boot wall about said aperture into engagement with the roller and thereby seal the aperture.

ERIC W. PETERSON. 

